95 lines
2.5 KiB
C
95 lines
2.5 KiB
C
/*
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* Support for DMA from PCI devices to main memory on
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* machines without an iommu or with directly addressable
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* RAM (typically a pmac with 2Gb of RAM or less)
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*
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* Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/delay.h>
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#include <linux/string.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/mm.h>
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#include <linux/dma-mapping.h>
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#include <asm/sections.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/pci-bridge.h>
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#include <asm/machdep.h>
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#include <asm/pmac_feature.h>
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#include <asm/abs_addr.h>
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#include <asm/ppc-pci.h>
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static void *pci_direct_alloc_coherent(struct device *hwdev, size_t size,
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dma_addr_t *dma_handle, gfp_t flag)
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{
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void *ret;
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ret = (void *)__get_free_pages(flag, get_order(size));
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if (ret != NULL) {
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memset(ret, 0, size);
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*dma_handle = virt_to_abs(ret);
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}
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return ret;
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}
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static void pci_direct_free_coherent(struct device *hwdev, size_t size,
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void *vaddr, dma_addr_t dma_handle)
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{
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free_pages((unsigned long)vaddr, get_order(size));
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}
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static dma_addr_t pci_direct_map_single(struct device *hwdev, void *ptr,
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size_t size, enum dma_data_direction direction)
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{
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return virt_to_abs(ptr);
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}
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static void pci_direct_unmap_single(struct device *hwdev, dma_addr_t dma_addr,
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size_t size, enum dma_data_direction direction)
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{
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}
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static int pci_direct_map_sg(struct device *hwdev, struct scatterlist *sg,
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int nents, enum dma_data_direction direction)
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{
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int i;
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for (i = 0; i < nents; i++, sg++) {
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sg->dma_address = page_to_phys(sg->page) + sg->offset;
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sg->dma_length = sg->length;
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}
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return nents;
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}
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static void pci_direct_unmap_sg(struct device *hwdev, struct scatterlist *sg,
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int nents, enum dma_data_direction direction)
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{
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}
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static int pci_direct_dma_supported(struct device *dev, u64 mask)
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{
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return mask < 0x100000000ull;
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}
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void __init pci_direct_iommu_init(void)
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{
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pci_dma_ops.alloc_coherent = pci_direct_alloc_coherent;
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pci_dma_ops.free_coherent = pci_direct_free_coherent;
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pci_dma_ops.map_single = pci_direct_map_single;
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pci_dma_ops.unmap_single = pci_direct_unmap_single;
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pci_dma_ops.map_sg = pci_direct_map_sg;
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pci_dma_ops.unmap_sg = pci_direct_unmap_sg;
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pci_dma_ops.dma_supported = pci_direct_dma_supported;
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}
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